Apparatus and method for self contained breathing

ABSTRACT

Embodiments described herein relate to a self-contained breathing apparatus, and more particularly, to a self-contained breathing apparatus that uses extraction and exchange of oxygen and carbon dioxide between a perfluorocarbon and water in which the apparatus is immersed. Embodiments include a water-to-perfluorocarbon exchange chamber; an air-to-perfluorocarbon exchange chamber; and a circulation pump, where the circulation pump is configured to circulate perfluorocarbon between the water-to-perfluorocarbon exchange chamber and the air-to-perfluorocarbon exchange chamber, where the perfluorocarbon becomes oxygen rich in response to passing through the water-to-perfluorocarbon exchange chamber, and where the perfluorocarbon becomes oxygen depleted in response to passing through the air-to-perfluorocarbon exchange chamber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 63/070,580, filed on Aug. 26, 2020, the contents of which are hereby incorporated by reference in their entirety.

TECHNOLOGICAL FIELD

An example embodiment of the present disclosure relates to a self-contained breathing apparatus, and more particularly, to a self-contained breathing apparatus that uses extraction and exchange of oxygen and carbon dioxide between a perfluorocarbon and water in which the apparatus is immersed.

BACKGROUND

The ability to breathe underwater has been instrumental in a variety of fields from diving exploration of the sea floor for commercial, scientific, and recreational to military use for strategic deployment of troops. Conventional underwater breathing apparatuses involve bulky, high-pressure oxygen tanks that have limited capacity thereby limiting range and depth of use. Further, underwater breathing using oxygen tanks produces air bubbles from exhaled breaths that can pose issues in various circumstances. For example, air bubbles exhaled from a diver can attract unwanted attention from both predators and human surveillance. Further, for recreational or scientific divers, air bubbles can affect the behavior of sea life around the diver. In exploration, exhaled air bubbles can fill an enclosed structure that is being explored by a diver, potentially disturbing the structure. Breathing underwater for indefinite periods without a tether to a surface vessel has long been the subject of science fiction and fantasy, with no realistic solution available.

BRIEF SUMMARY

A method, apparatus, and computer program product are provided in accordance with an example embodiment for a self-contained breathing apparatus, and more particularly, to a self-contained breathing apparatus that uses extraction and exchange of oxygen and carbon dioxide between a perfluorocarbon and water in which the apparatus is immersed. Embodiments may include an apparatus having: a water-to-perfluorocarbon exchange chamber; an air-to-perfluorocarbon exchange chamber; and a circulation pump, where the circulation pump is configured to circulate perfluorocarbon between the water-to-perfluorocarbon exchange chamber and the air-to-perfluorocarbon exchange chamber, where the perfluorocarbon becomes oxygen rich in response to passing through the water-to-perfluorocarbon exchange chamber, and where the perfluorocarbon becomes oxygen depleted in response to passing through the air-to-perfluorocarbon exchange chamber.

According to an example embodiment, the water-to-perfluorocarbon exchange chamber includes a chamber defining a volume therein, where the perfluorocarbon is cycled through a stacked latticework of gas-permeable tubing within the chamber, and where water is passed through the chamber across the stacked latticework of gas-permeable tubing. According to this embodiment, carbon dioxide is passed from the perfluorocarbon to the water through the gas-permeable tubing, and wherein oxygen is passed from the water to the perfluorocarbon through the gas-permeable tubing. According to an example embodiment, the air-to-perfluorocarbon exchange chamber includes a chamber defining a volume there, wherein the perfluorocarbon is cycled through a latticework of gas-permeable tubing within the chamber, and where air is passed through the chamber across the stacked latticework of gas-permeable tubing. According to this embodiment, carbon dioxide is passed from the air to the perfluorocarbon through the gas-permeable tubing, and wherein oxygen is passed from the perfluorocarbon to the air through the gas-permeable tubing. The gas-permeable polymer tubing of an example embodiment includes gas-permeable polymer tubing.

Embodiments may include a controller and an oxygen concentration sensor, where the controller may be configured to control a speed of the circulation pump in response to sensor information from the oxygen concentration sensor. According to an example embodiment, an air circuit may pass through the air-to-perfluorocarbon exchange chamber, where the air circuit includes a mouthpiece, and where the air circuit provides oxygen-depleted exhaled air to the air-to-perfluorocarbon exchange chamber and receives oxygen-enriched air to the mouthpiece.

Embodiments provided herein include a method including: propelling oxygen-depleted gas through an air-to-perfluorocarbon exchange chamber; pumping an oxygen-rich perfluorocarbon into the air-to-perfluorocarbon exchange chamber; enriching the oxygen depleted gas with oxygen in the air-to-perfluorocarbon exchange chamber to form oxygen-rich gas exiting the air-to-perfluorocarbon exchange chamber; and receiving from the air-to-perfluorocarbon exchange chamber oxygen-depleted perfluorocarbon. The method of an example embodiment further includes: circulating the oxygen-rich perfluorocarbon through a stacked latticework of gas-permeable tubing within a chamber of the air-to-perfluorocarbon exchange chamber; circulating the oxygen-depleted gas over the stacked latticework of gas-permeable tubing within the chamber of the air-to-perfluorocarbon exchange chamber, wherein oxygen from the oxygen-rich perfluorocarbon is exchanged with carbon dioxide from the oxygen-depleted gas to form oxygen-rich gas and oxygen-depleted perfluorocarbon in response to the oxygen-rich perfluorocarbon circulating through the stacked latticework of gas-permeable tubing within the chamber and the oxygen-depleted gas circulating over the stacked latticework of gas-permeable tubing within the chamber.

Methods of an example embodiment further include: pumping oxygen-depleted perfluorocarbon into a water-to-perfluorocarbon exchange chamber; pumping oxygen-rich water into the water-to-perfluorocarbon exchange chamber; and exchanging oxygen from the oxygen-rich water with carbon dioxide from the oxygen-depleted perfluorocarbon within the water-to-perfluorocarbon exchange chamber. According to some embodiments, exchanging oxygen from the oxygen-rich water with carbon dioxide from the oxygen-depleted perfluorocarbon within the water-to-perfluorocarbon exchange chamber includes pumping the perfluorocarbon through a stacked latticework of gas-permeable polymer tubing within the water-to-perfluorocarbon exchange chamber and pumping oxygen-rich water across the stacked latticework of gas-permeable polymer tubing.

Embodiments provided herein include a system including: a water-to-perfluorocarbon exchange chamber comprising a first latticework of gas-permeable tubing, where a first circuit within the water-to-perfluorocarbon exchange chamber includes a flow path through the gas-permeable tubing of the first latticework of gas-permeable tubing and a second circuit within the water-to-perfluorocarbon exchange chamber includes a flow path across the first latticework of gas-permeable tubing; an air-to-perfluorocarbon exchange chamber including a second latticework of gas-permeable tubing, where a first circuit within the air-to-perfluorocarbon exchange chamber includes a flow path through the gas-permeable tubing of the second latticework of gas-permeable tubing and a second circuit within the air-to-perfluorocarbon exchange chamber includes a flow path across the second latticework of gas-permeable tubing; and a perfluorocarbon circulation pump configured to circulate perfluorocarbon through the first circuit of the water-to-perfluorocarbon exchange chamber and through the second circuit of the air-to-perfluorocarbon exchange chamber.

According to some embodiments, the system includes a water circulation pump configured to circulate water through the second circuit of the water-to-perfluorocarbon exchange chamber. According to an example embodiment, oxygen-depleted air is received through the second circuit of the air-to-perfluorocarbon exchange chamber and exchanges carbon dioxide for oxygen with the perfluorocarbon within the air-to-perfluorocarbon exchange chamber. Embodiments of the system optionally include at least one of a facemask or mouthpiece configured to receive oxygen-rich gas from the second circuit of the air-to-perfluorocarbon exchange chamber and to return oxygen-depleted gas to the second circuit of the air-to-perfluorocarbon exchange chamber. The system optionally includes at least one one-way valve to promote gas flow in one direction from the second circuit of the air-to-perfluorocarbon exchange chamber.

A system of an example embodiment optionally includes an oxygen concentration sensor and an oxygen tank, where oxygen from the oxygen tank is introduced to a flow of gas from the second circuit of the air-to-perfluorocarbon exchange chamber before the at least one of the facemask or mouthpiece in response to a signal from the oxygen concentration sensor indicating oxygen concentration below a predetermined threshold. According to an example embodiment, the first latticework of gas-permeable tubing includes a first latticework of gas-permeable polymer tuning, and where the second latticework of gas-permeable tubing includes a second latticework of gas-permeable polymer tubing.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus described example embodiments of the disclosure in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

FIG. 1 is a schematic illustration of a self-contained underwater breathing apparatus according to an example embodiment of the present disclosure;

FIG. 2 is a schematic illustration of a self-contained underwater breathing apparatus highlighting the air circuit according to an example embodiment of the present disclosure;

FIG. 3 is a schematic illustration of a self-contained underwater breathing apparatus highlighting a portion of the perfluorocarbon circuit according to an example embodiment of the present disclosure;

FIG. 4 is a schematic illustration of a self-contained underwater breathing apparatus highlighting another portion of the perfluorocarbon circuit according to an example embodiment of the present disclosure;

FIG. 5 is a schematic illustration of a self-contained underwater breathing apparatus highlighting yet another portion of the perfluorocarbon circuit according to an example embodiment of the present disclosure;

FIG. 6 is a schematic illustration of a self-contained underwater breathing apparatus highlighting still another portion of the perfluorocarbon circuit according to an example embodiment of the present disclosure;

FIG. 7 is a schematic illustration of a self-contained underwater breathing apparatus including a controller and an oxygen tank according to an example embodiment of the present disclosure; and

FIG. 8 illustrates another embodiment of a self-contained underwater breathing apparatus in a body-worn form factor according to an example embodiment of the present disclosure.

DETAILED DESCRIPTION

Example embodiments of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, embodiments of the invention are shown. Indeed, various embodiments of the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout.

Embodiments provided herein include a self-contained breathing apparatus that allows an end-use to breathe underwater, potentially indefinitely, without the need for compressed, oxygenated air. The apparatus of example embodiments function as an artificial, external gill and accomplishes this through the extraction of oxygen from surrounding water and enriching an exhaled breath with the extracted oxygen. Carbon dioxide is extracted from exhaled breaths and expelled into the surrounding water. This allows the user to inhale adequate amounts of oxygen with each breath while eliminating carbon dioxide from the expelled breaths.

Embodiments of the present disclosure use perfluorocarbons (PFCs) as the medium to exchange oxygen and carbon dioxide between recirculated breathing air and surrounding water. PFCs have high oxygen solubility such that they are suitable for use in the embodiments described herein to draw oxygen from water, and enrich oxygen-depleted air with the oxygen. While PFCs have been considered for liquid breathing, whereby a user inhales liquid PFC into their lungs, such liquid breathing can be traumatic and requires substantial preparation time for the user and requires expelling of the fluid from the lungs when returning the user to breathing air. Embodiments described herein provide a mechanism by which liquid is not received into the lungs such that the user preparation and expelling of fluid from the lungs is not required. Further, embodiments may be worn by a user requiring little to no preparation time, and may be removed from a user with the ease of physical removal of the body-worn apparatus.

In order to exchange the oxygen and carbon dioxide between the PFC and both the exhaled breaths and the water surrounding the disclosed apparatus, embodiments employ two distinct sets of gas exchange circuits, with each circuit containing a stacked latticework of ultra-fine, gas-permeable tubing that allows rapid gas exchange and equilibration between the liquid or gas inside the tubing and the liquid or gas outside the tubing. Using a stacked latticework of ultra-fine, gas-permeable tubing provides a large surface area of the tubing through which the oxygen and carbon-dioxide passes during operation. This large surface area provides sufficient gas exchange to support the oxygen needs of a person using the apparatus. The gas-permeable tubing of an example embodiment includes a gas-permeable polymer tubing. Further, the gas-permeable tubing is in some embodiments made of other permeable and semi-permeable membranes such as those mad of metal, glass, or ceramic. The gas-permeable tubing material selection is based on individual use cases, embodiments of which sacrifice lower-cost materials such as polymer tubing for those made of more expensive materials that provide greater longevity and durability, particularly if a perfluorocarbon is used that degrades certain materials over time.

While uses of example embodiments of the self-contained breathing apparatus described herein may use powered propulsion devices such as underwater propellers or vehicles on which a user may ride or otherwise secure themselves to, embodiments may also be employed by users moving under their own power. In such embodiments, a user may exert effort to propel themselves through the water, such as using swim fins or even bare hands and feet. As a user may be exerting themselves to some degree while wearing embodiments of the present disclosure, the self-contained breathing apparatus may be sized according the perceived requirements of a user that is consuming more oxygen than at a resting heart rate. Further, the apparatus of example embodiments may be sized according to a user's size, with larger individuals generally requiring more oxygen. The size of the physical package of the self-contained breathing apparatus described herein may be consistent among different sizes, with the size difference realized in the latticework of ultra-fine, gas-permeable polymer tubing. The amount of oxygen exchanged is dependent upon the flow of the PFCs, the flow of the water around the latticework, and the amount of surface area provided by the lattice work for exchange.

As described above, the apparatus of example embodiments uses two distinct sets of gas exchange circuits. The first circuit allows for gas exchange between the user's exhaled breaths and a halogenated carbon compound or perfluorocarbon (PFC) that is capable of binding and releasing both carbon dioxide and oxygen. The second circuit allows for gas exchange between the PFC and the surrounding water. The PFC acts as a go-between by: A) extraction of carbon dioxide from expelled breaths, and exchanging it with the surrounding water thereby preventing carbon dioxide toxicity (hypercarbia); and B) extraction of oxygen from the surrounding water and exchanging it with the oxygen-depleted expelled breaths, thus maintaining oxygenation.

FIG. 1 is a schematic illustration of the self-contained breathing apparatus 100 according to an example embodiment of the present disclosure. The illustrated embodiment is depicted without a housing or means to attach to a wearer. However, embodiments may include a suitable housing to support the components shown in the schematic illustration with appropriate flow channels for water, air, and PFC. Further, means to attach to a user may include straps such as shoulder straps and may include cross-body straps such as a waist strap and/or a strap connecting shoulder straps across the chest.

The schematic illustration of FIG. 1 includes a self-contained breathing apparatus 100 having an air circuit 102 that is a substantially closed circuit other than the interface of the air circuit with the latticework of ultra-fine gas-permeable tubing within the air-to-PFC exchange chambers 120 and 220 and the mouthpiece 110 through which a user breathes. The apparatus of the illustrated embodiment includes two redundant circuits 104 and 106 that are each used to remove carbon dioxide from exhaled air and expel the carbon dioxide to the water surrounding the apparatus, while extracting oxygen from the water and enriching the air in the air circuit 102 with the oxygen. The self-contained breathing apparatus 100 further includes water-to-PFC exchange chambers 140 and 240 having water inlets 142 and 242 respectively, and water outlets 144 and 244 respectively. Also shown are water circulation pumps 146 and 246 attached to or housed within the water-to-PFC exchange chambers 140 and 240. The PFC circulates through the apparatus using PFC circulation pumps 130 and 230.

FIG. 2 illustrates the schematic representation of the apparatus 100 including arrows of flow direction, and depicts the air circuit 102 as shaded. The mouthpiece 110 is representative of the portion of the air circuit 110 engaged by a user's mouth, though embodiments may include a full-face mask. As a user inhales, air is drawn through the left-branch 116 of the air circuit 102 which includes oxygen-rich air. The oxygen-rich air is drawn in through the mouthpiece 110, through one-way valve 112. One-way valves 112 and 114 ensure that during inhalation by the user, air is drawn only from the left branch 116 of the air circuit 102. The user then exhales through mouthpiece 110 and the air is forced through one-way valve 114 to the right-branch 118 of the air circuit 102. The right-branch 118 of the air circuit 102 includes oxygen-depleted air that is rich in carbon dioxide. The exhaled air travels along the right-branch 118 of the air circuit 102 to the first air-to-PFC exchange chamber 120, where the air passes through a stacked latticework of ultra-fine gas-permeable tubing within the chamber. As the oxygen-depleted, carbon dioxide-rich air passes through the latticework, the PFC flowing through the gas-permeable tubing causes the carbon dioxide to bind with the PFC, while the PFC emits oxygen into the air. Thus, the air becomes depleted of carbon dioxide and enriched with oxygen.

The air passing through the first air-to-PFC exchange chamber 120 exits the chamber and passes through a one-way valve 122 to the second air-to-PFC exchange chamber 220. The second air-to-PFC exchange chamber includes another stacked latticework of ultra-fine gas-permeable tubing within the chamber. The air is further depleted of carbon dioxide while being further enriched with oxygen. The second air-to-PFC exchange chamber 220 may not be necessary in some embodiments. However, including the second air-to-PFC exchange chamber enhances the capacity of the apparatus 102 to handle greater levels of oxygen depletion in the exhaled air while depleting the air of carbon dioxide. The redundant circuits 104 and 106 illustrated in FIG. 1 provide a modular and scalable architecture that enables greater oxygen/carbon dioxide exchange as needed. Further, the size of the chambers of the circuits can be scaled to the size needed to sufficiently exchange exhaled carbon dioxide for oxygen.

FIG. 3 illustrates the PFC flow circuit from the first air-to-PFC exchange chamber 120 to the first water-to-PFC exchange chamber 140 including direction flow arrows. As shown, the liquid PFC flows from the first air-to-PFC exchange chamber 120 to the first water-to-PFC exchange chamber 140 through a conduit and the flow is facilitated by a circulating pump 130. The circulating pump may be of any conventional fluid pump types, such as an axial-flow pump or centrifugal flow pump, dependent upon the configuration of the circuit 104 of the apparatus 100. The pump may operate with constant flow to circulate the PFC through the exchange chambers. It is desirable for the pump to be an electrically powered high-efficiency pump to minimize the power consumption of the apparatus 100. The pump may be powered by a battery (not shown) of the apparatus 100, such as a lithium-ion battery pack. Optionally, an emergency back-up power source may also be employed, which may include an auxiliary battery pack, salt cell, or even a manually operated auxiliary power source. Further, embodiments may include a manual pump to function in lieu of the circulation pump 130 in the event to power loss.

The PFC circulated through circulation pump 130 enters the first water-to-PFC exchange chamber 140. The first water-to-PFC exchange chamber includes a stacked latticework of ultra-fine gas-permeable polymer tubing as in the air-to-PFC exchange chambers. The PFC is circulated through the ultra-fine gas-permeable polymer tubing, while water is pumped across the stacked latticework. Water is circulated through the first water-to-PFC exchange chamber by pump 146, which may be any pump capable of moving water across the stacked latticework with sufficient volume to achieve the desired effects described herein. The water is drawn in through inlet 142 and expelled through outlet 144. As the water passes over the stacked latticework of ultra-fine gas-permeable polymer tubing, and as the PFC is circulated through the tubing, the PFC is depleted of carbon dioxide by the water, while the PFC is enriched with oxygen from the water.

FIG. 4 illustrates the return of oxygen-enriched PFC from the first water-to-PFC exchange chamber to the first air-to-PFC exchange chamber 120. The oxygen-enriched PFC is then used by the first air-to-PFC exchange chamber 120 to deplete the exhaled air of carbon dioxide while enriching the air with oxygen. FIG. 5 illustrates the second circuit 104 pumping oxygen-depleted PFC from the second air-to-PFC exchange chamber 220 to the second water-to-PFC exchange chamber 240. The second water-to-PFC exchange chamber 240 functions in the same way as the first water-to-PFC exchange chamber to deplete the PFC of carbon dioxide and enrich the PFC with oxygen. The oxygen-enriched PFC is returned to the second air-to-PFC exchange chamber 220 as shown in the shaded flow of FIG. 6. The air flowing through the second air-to-PFC exchange chamber 220 has been partially enriched with oxygen from the first air-to-PFC exchange chamber 120 while simultaneously being partially depleted of carbon dioxide. The second air-to-PFC exchange chamber 220 further enriches the air with oxygen while further depleting the air of carbon dioxide.

Oxygen and carbon dioxide content of the air in the air circuit may be monitored to ensure the depletion of carbon dioxide from the exhaled air is sufficient while also ensuring that oxygen enrichment of the air returned to the user is sufficient to satisfy the oxygen needs of the user. The oxygen and carbon dioxide content may be measured using gas-sampling and monitoring, such as using a spectroscopy-based system. As illustrated in FIG. 7, embodiments may include an oxygen-concentration measurement device 202 which may also measure carbon dioxide concentration in the air returned to the user. Embodiments may also include an gas concentration measurement device 204 on the air exhaled from the user, which can identify the portion of the oxygen delivered to the user consumed by the user. Computer integration of the measurement device 202, 204, may be used to provide alarm or notification if oxygen content of the air delivered to the user falls outside of safe breathable limits. Computer integration may further adjust pump speeds for the circulation pumps 130, 230 of the PFC between the air-to-PFC exchange chambers 120, 220 and the water-to-PFC exchange chambers 140, 240. The pump speeds for the water pumps 146, 246 to flow more water across the stacked latticework of ultra-fine gas-permeable polymer tubing to facilitate greater gas exchange. Using variable pump speeds may provide energy savings and improve the efficiency with which the apparatus 100 functions.

In addition to monitoring the oxygen content of the air breathed by a user, the oxygen content of the water pumped through the water-to-PFC exchange chambers may be monitored. Oxygen content in water may vary depending upon the environment. In water with a lower oxygen content, the speed of pumps 146, 246 may be increased to facilitate greater extraction of oxygen from the water.

In the event that sufficient oxygen cannot be extracted from the water through the two water-to-PFC exchange chambers 140, 240 to enrich the air through the air-to-PFC exchange chambers 120, 220, embodiments may include a supplemental compressed oxygen tank 210 as shown in FIG. 7. The supplemental compressed oxygen tank 210 may be small but sufficient to supplement air returned to a user with oxygen to maintain oxygen levels above a predefined minimum level. The volume of the tank may be sufficient to enable a user to safely reach the surface of the water to breath normally without the apparatus. The supplemental compressed oxygen tank 210 may also be employed in the event of failure of any or all of the components of the apparatus 100, such as through leaks in the PFC system, power failure to the pumps, pump seizure, or the like.

FIG. 7 also illustrates the controller 225 which may be in wired or wireless communication with the circulation pumps 130, 230, water pumps 146, 246, gas concentration measurement devices 202, 204, etc. The controller may control the speed of the various pumps based on feedback from the gas concentration measurement devices 202, 204 in a closed-loop system. Embodiments may also operate in an open-loop system where feedback from the measurement devices, 204, is not essential. The controller 225 may further control the release of oxygen from the oxygen tank 210 when oxygen concentration in the air being returned to a user falls below a predefined minimum.

The controller may be embodied in a number of different ways. For example, the controller may include a processor or processing circuitry, where a processor may be embodied as one or more of various hardware processing means such as a coprocessor, a microprocessor, a controller, a digital signal processor (DSP), a processing element with or without an accompanying DSP, or various other processing circuitry including integrated circuits such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), a microcontroller unit (MCU), a hardware accelerator, a special-purpose computer chip, or the like. As such, in some embodiments, the processor may include one or more processing cores configured to perform independently. The controller may receive, as input, feedback from the pumps and/or the gas concentration measurement devices in order to control the pump speeds and to provide alerts as needed to a user.

In an example embodiment, the controller may be configured to execute instructions stored in a memory of the controller or otherwise accessible to the processor or processing circuitry. Alternatively or additionally, the processor may be configured to execute hard coded functionality. As such, whether configured by hardware or software methods, or by a combination thereof, the processor may represent an entity (for example, physically embodied in circuitry) capable of performing operations according to an embodiment of the present disclosure while configured accordingly. Thus, for example, when the processor is embodied as an ASIC, FPGA or the like, the processor may be specifically configured hardware for conducting the operations described herein. Alternatively, as another example, when the processor is embodied as an executor of software instructions, the instructions may specifically configure the processor to perform the algorithms and/or operations described herein when the instructions are executed. However, in some cases, the processor may be a processor of a specific device (for example, the computing device) configured to employ an embodiment of the present disclosure by further configuration of the processor by instructions for performing the algorithms and/or operations described herein. The processor may include, among other things, a clock, an arithmetic logic unit (ALU) and logic gates configured to support operation of the processor.

While the aforementioned embodiments include air-to-PFC and water-to-PFC chambers that may be worn by a user in “tanks” or other structural configuration, embodiments may include different form factors. FIG. 8 illustrates an example form factor where the system is worn in the form of a garment or wetsuit 300. The water-to-PFC chamber of the illustrated embodiment of FIG. 8 is replaced by gas permeable tubing 310 woven onto the wetsuit 300 and configured to conduct perfluorocarbon through the gas permeable tubing 310. Water flowing over the wetsuit 300, such as when a wearer is diving, swimming, or is otherwise immersed in water, flows over the gas permeable tubing 310 and exchanges oxygen from the water with carbon dioxide from the perfluorocarbon. This is facilitated by the perfluorocarbon flowing in a single direction through the gas permeable tubing 310. The oxygen-rich perfluorocarbon is delivered to an air-to-PFC exchange system. This may be embodied in the form of a radiator-like structure where oxygen-depleted air flows across gas permeable tubing and exchanges carbon dioxide for oxygen with the oxygen-rich perfluorocarbon.

According to the illustrated embodiment of FIG. 8, the air-to-PFC exchange system may be incorporated into a mask 320, where oxygen-rich perfluorocarbons flow from the wetsuit 300, through a conduit 330 to the air-to-PFC exchange system in the mask 320. Optionally, the air-to-PFC exchange system may be incorporated into the wetsuit 300 or is otherwise worn by a user, such as using a small tank that receives perfluorocarbon from the gas permeable tubing 310 and receives oxygen-depleted air from the mask 320, and returns oxygen-depleted perfluorocarbon to the gas permeable tubing 310 and oxygen-rich air to the mask 320. The one-way flow of air may be facilitated by one-way valves as described in the system above to ensure oxygen-depleted air is carried away from a wearer, while oxygen-rich air is delivered to the wearer.

Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. 

That which is claimed:
 1. An apparatus comprising: a water-to-perfluorocarb on exchange chamber; an air-to-perfluorocarbon exchange chamber; and a circulation pump, wherein the circulation pump is configured to circulate perfluorocarbon between the water-to-perfluorocarbon exchange chamber and the air-to-perfluorocarbon exchange chamber, wherein the perfluorocarbon becomes oxygen rich in response to passing through the water-to-perfluorocarbon exchange chamber, and wherein the perfluorocarbon becomes oxygen depleted in response to passing through the air-to-perfluorocarbon exchange chamber.
 2. The apparatus of claim 1, wherein the water-to-perfluorocarbon exchange chamber comprises a chamber defining a volume therein, wherein the chamber contains a stacked latticework of gas-permeable tubing, wherein the perfluorocarbon is cycled through the stacked latticework of gas-permeable tubing within the chamber, and wherein water is passed through the chamber across the stacked latticework of gas-permeable tubing.
 3. The apparatus of claim 2, wherein carbon dioxide is passed from the perfluorocarbon to the water through gas-permeable tubing of the stacked latticework of gas-permeable tubing in the water-to-perfluorocarbon exchange chamber, and wherein oxygen is passed from the water to the perfluorocarbon through the gas-permeable tubing.
 4. The apparatus of claim 3, wherein the air-to-perfluorocarbon exchange chamber comprises a chamber defining a volume therein and containing a stacked latticework of gas-permeable tubing, wherein the perfluorocarbon is cycled through the latticework of gas-permeable tubing of the stacked latticework of gas-permeable tubing within the chamber of the air-to-perfluorocarbon exchange chamber, and wherein air is passed through the chamber across the stacked latticework of gas-permeable tubing in the air-to-perfluorocarbon exchange chamber.
 5. The apparatus of claim 4, wherein carbon dioxide is passed from the air to the perfluorocarbon through the gas-permeable tubing, and wherein oxygen is passed from the perfluorocarbon to the air through the gas-permeable tubing.
 6. The apparatus of claim 5, wherein the gas-permeable tubing comprises a gas-permeable polymer tubing.
 7. The apparatus of claim 1, further comprising: a controller; and an oxygen concentration sensor, wherein the controller is configured to control a speed of the circulation pump in response to sensor information from the oxygen concentration sensor.
 8. The apparatus of claim 1, further comprising: a controller; an oxygen concentration sensor; and a supplemental oxygen tank, wherein oxygen gas from the supplemental oxygen tank is introduced to air from the air-to-perfluorocarbon exchange chamber in response to a signal from the oxygen concentration sensor indicating oxygen concentrations below a threshold value.
 9. The apparatus of claim 1, further comprising: an air circuit passing through the air-to-perfluorocarbon exchange chamber, wherein the air circuit comprises a mouthpiece, and wherein the air circuit provides oxygen-depleted exhaled air to the air-to-perfluorocarbon exchange chamber and receives oxygen-enriched air to the mouthpiece.
 10. A method for exchanging carbon dioxide gas with oxygen comprising: propelling oxygen-depleted gas through an air-to-perfluorocarbon exchange chamber; pumping an oxygen-rich perfluorocarbon into the air-to-perfluorocarbon exchange chamber; enriching the oxygen-depleted gas with oxygen in the air-to-perfluorocarbon exchange chamber to form oxygen-rich gas exiting the air-to-perfluorocarbon exchange chamber; and receiving from the air-to-perfluorocarbon exchange chamber oxygen-depleted perfluorocarbon.
 11. The method of claim 10, further comprising: circulating the oxygen-rich perfluorocarbon through a stacked latticework of gas-permeable tubing within a chamber of the air-to-perfluorocarbon exchange chamber; and circulating the oxygen-depleted gas over the stacked latticework of gas-permeable tubing within the chamber of the air-to-perfluorocarbon exchange chamber, wherein oxygen from the oxygen-rich perfluorocarbon is exchanged with carbon dioxide from the oxygen-depleted gas to form oxygen-rich gas and oxygen-depleted perfluorocarbon in response to the oxygen-rich perfluorocarbon circulating through the stacked latticework of gas-permeable tubing within the chamber and the oxygen-depleted gas circulating over the stacked latticework of gas-permeable tubing within the chamber.
 12. The method of claim 11, further comprising: pumping oxygen-depleted perfluorocarbon into a water-to-perfluorocarbon exchange chamber; pumping oxygen-rich water into the water-to-perfluorocarbon exchange chamber; and exchanging oxygen from the oxygen-rich water with carbon dioxide from the oxygen-depleted perfluorocarbon within the water-to-perfluorocarbon exchange chamber.
 13. The method of claim 12, wherein exchanging oxygen from the oxygen-rich water with carbon dioxide from the oxygen-depleted perfluorocarbon within the water-to-perfluorocarbon exchange chamber comprises pumping the perfluorocarbon through a stacked latticework of gas-permeable polymer tubing within the water-to-perfluorocarbon exchange chamber and pumping oxygen-rich water across the stacked latticework of gas-permeable polymer tubing.
 14. A system including: a water-to-perfluorocarbon exchange chamber comprising a first latticework of gas-permeable tubing, wherein a first circuit within the water-to-perfluorocarbon exchange chamber comprises a flow path through the gas-permeable tubing of the first latticework of gas-permeable tubing and a second circuit within the water-to-perfluorocarbon exchange chamber comprises a flow path across the first latticework of gas-permeable tubing; an air-to-perfluorocarbon exchange chamber comprising a second latticework of gas-permeable tubing, wherein a first circuit within the air-to-perfluorocarbon exchange chamber comprises a flow path through the gas-permeable tubing of the second latticework of gas-permeable tubing and a second circuit within the air-to-perfluorocarbon exchange chamber comprises a flow path across the second latticework of gas-permeable tubing; and a perfluorocarbon circulation pump configured to circulate perfluorocarbon through the first circuit of the water-to-perfluorocarbon exchange chamber and through the second circuit of the air-to-perfluorocarbon exchange chamber.
 15. The system of claim 14, further comprising: a water circulation pump configured to circulate water through the second circuit of the water-to-perfluorocarbon exchange chamber.
 16. The system of claim 15, wherein oxygen-depleted air is received through the second circuit of the air-to-perfluorocarbon exchange chamber and exchanges carbon dioxide for oxygen with the perfluorocarbon within the air-to-perfluorocarbon exchange chamber.
 17. The system of claim 16, further comprising at least one of a facemask or mouthpiece configured to receive oxygen-rich gas from the second circuit of the air-to-perfluorocarbon exchange chamber and to return oxygen-depleted gas to the second circuit of the air-to-perfluorocarbon exchange chamber.
 18. The system of claim 17, further comprising at least one one-way valve to promote gas flow in one direction from the second circuit of the air-to-perfluorocarbon exchange chamber.
 19. The system of claim 18, further comprising an oxygen concentration sensor and an oxygen tank, wherein oxygen from the oxygen tank is introduced to a flow of gas from the second circuit of the air-to-perfluorocarbon exchange chamber before the at least one of the facemask or mouthpiece in response to a signal from the oxygen concentration sensor indicating oxygen concentration below a predetermined threshold.
 20. The system of claim 14, wherein the first latticework of gas-permeable tubing comprises a first latticework of gas-permeable polymer tubing and wherein the second latticework of gas-permeable tubing comprises a second latticework of gas-permeable polymer tubing. 